Brittlefisj are like starfish but instead of the usual triangles you see on a starfish, it's five tentacles that can be as tall as I think 5 meters. As defense, they can literally dispose of one of their limbs, aka severe a tentacle at any place. It's not dangerous, but it's kinda scary to look at. But you might not encounter those easily, as they can go as deep as 5km deep in the sea, in the abyss, where sunlight is not a part of the dictionary. Also, some stuff I wanted to let ya know:

• Scientists don't think starfish are related to fishes in any way besides being underwater, so they want to rename them sea stars. Honestly I like that.

• And also if you see a starfish of any kind dont touch them or even disturb them, they are threatened to go instinct, and touching them might make it worse. We're currently trying to make them recover from that so please dont do that.